When addr is out of the range of the whole rb_tree, pprev will points to
the right-most node. rb_tree facility already provides a helper
function, rb_last, to do this task. We can leverage this instead of
re-implement it.
This patch refines find_vma_prev with rb_last to make it a little nicer
to read.
Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
---
v2: leverage rb_last
---
mm/mmap.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 7e8c3e8ae75f..f7ed0afb994c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2270,12 +2270,9 @@ find_vma_prev(struct mm_struct *mm, unsigned long addr,
if (vma) {
*pprev = vma->vm_prev;
} else {
- struct rb_node *rb_node = mm->mm_rb.rb_node;
- *pprev = NULL;
- while (rb_node) {
- *pprev = rb_entry(rb_node, struct vm_area_struct, vm_rb);
- rb_node = rb_node->rb_right;
- }
+ struct rb_node *rb_node = rb_last(&mm->mm_rb);
+ *pprev = !rb_node ? NULL :
+ rb_entry(rb_node, struct vm_area_struct, vm_rb);
}
return vma;
}
--
2.17.1
